Change process name without changing argv[0] in Linux

I need to modify the process name of my program in C language.
I precise, this is not the name of a thread that I want to change.
I want to change the name of my program, but the only solution I found, is to modify the value of argv[0].
I also found another solution with prctl(PR_SET_NAME, "newname"), but this solution doesn't work.